Renal ultrasound should always include a bladder assessment (covered in the prerequisite KidSONO Bladder Volume Module). However, In the context of hydronephrosis, additional imaging of the bladder with color Doppler is needed to assess for ureteric jets, as their presence or absence may indicate ureteric obstruction.

*For details on bladder scanning technique and protocol, please refer to the prerequisite KidSONO Bladder Volume module prior to continuing with this module.

 

Normal Ureteric jets

Urine flows from the kidney, through the ureters, and finally enters the bladder at the trigone. Ultrasound “Ureteral Jets” are a color Doppler finding during bladder ultrasound that detects the flow of urine into the bladder at the level of the trigone.   As urine flows into a filled bladder, the ureteral jets appear as color signals that flow in an anteromedial direction and should cross the midline [11].

 

Assessing for Ureteric Jets:

• In the transverse plane, apply color or power doppler along the posterior wall of the bladder around the trigone
• Use a low flow scale 10-20cm/s with doppler box placed over the posterior wall.
• Of note, urine is not continuously released into the bladder so you may need to wait up to 5-10 minutes to see if there are any ureteral jets in the bladder.

 

Figure 8: Transverse bladder with power doppler displaying normal ureteric jets. Image use with permission from the Pocus Atlas [12]